#include

#include

#include

#include

class Book $\{$

private:

std::string title;

std::string author;

int id;

bool isAvailable;

public:

Book$($std::string t$,$ std::string a$,$ int i$)$ : title$($t$),$ author$($a$),$ id$($i$),$ isAvailable$($true$)\{\}$

void borrowBook$()\{$

if$($isAvailable$)\{$

isAvailable $=$ false;

$\}$ else $\{$

std::cout $<<$ "Book already borrowed." $<<$ std::endl;

$\}$

$\}$

void returnBook$()\{$

isAvailable $=$ true;

$\}$

void displayInfo$()\{$

std::cout $<<$ "Book: $"<<$ title $<<",$ Author: $"<<$ author $<<",$ ID: $"<<$ id

$<<",$ Available: $"<<($isAvailable $?$ "Yes" : $"$No$")<<$ std::endl;

$\}$

$\}$;

class Library $\{$

private:

std::vector books;

public:

void addBook$($Book book$)\{$

books.push$\_$back$($book$)$;

$\}$

void displayAllBooks$()\{$

for$($int i $=0$; i $<$ books.size$()$; i$++)\{$

books$[$i$].$displayInfo$()$;

$\}$

$\}$

Book$*$ findBookById$($int id$)\{$

for$($int i $=0$; i $<$ books.size$()$; i$++)\{$

if$($books$[$i$].$getId$()==$ id$)\{$

return &books$[$i$]$;

$\}$

$\}$

return NULL;

$\}$

$\}$;

void saveLibraryData$($Library &lib$)\{$

std::ofstream file$("$library$.$txt$")$;

lib.displayAllBooks$()$;

file.close$()$;

$\}$

int main$()\{$

Library myLibrary;

Book book$1("1984",$ "George Orwell", $101)$;

Book book$2("$To Kill a Mockingbird", "Harper Lee", $102)$;

Book book$3("$The Great Gatsby", $"$F$.$ Scott Fitzgerald", $103)$;

myLibrary.addBook$($book$1)$;

myLibrary.addBook$($book$2)$;

myLibrary.addBook$($book$3)$;

myLibrary.displayAllBooks$()$;

Book$*$ book $=$ myLibrary.findBookById$(102)$;

if$($book $!=$ NULL$)\{$

book$->$borrowBook$()$;

$\}$

myLibrary.displayAllBooks$()$;

saveLibraryData$($myLibrary$)$;

return $0$;

$\}$

This program aims to represent a simple library management system but contains several intentional errors, bad practices, and areas for improvement. It's a great exercise to review this code, identify the errors, and think about how you would correct them.